Pobierz PDF

original papers
Adv Clin Exp Med 2011, 20, 4, 441–445
ISSN 1230-025X
© Copyright by Wroclaw Medical University
Łukasz Szylberg1, Andrzej Marszałek2, 3
Myocardial Infarction Correlated with the Age
and Gender of the Patient in Autopsy Examinations
Zawał mięśnia sercowego w badaniu autopsyjnym a wiek i płeć chorego
Department of Clinical Pathology, University Hospital No. 1 in Bydgoszcz, Poland
Chair of Clinical Pathomorphology, Nicolaus Copernicus University Collegium Medicum in Bydgoszcz, Poland
3
Chair of Clinical Pathomorphology, Poznan University of Medical Sciences, Poland
1
2
Abstract
Background. Infarction can occur at practically any age, but the risk increases significantly with age; this is mainly
associated with the progressive development of atherosclerosis. In addition, males are significantly more predisposed to infarction than pre-menopausal women are, due to the protective effects of estrogen in the reproductive
age period. There have been many diagnostic tests showing significant narrowing of coronary arteries and indicating the location of myocardial infarction. In terms of pathomorphology, autopsy examinations allow confirmation
of the exact location and evaluation of a fatal heart attack.
Objectives. The aim of this study was to define the location of myocardial infarction in pathomorphological terms,
and to investigate the correlation with age and gender.
Material and Methods. The main inclusion criterion used in this study was the macroscopically and microscopically diagnosis of myocardial infarction in autopsy material. The number of myocardial infarctions in the group
analyzed was established using post-mortem records. Data on the specific localization of the myocardial infarction
was noted as well. Using the available clinical data, the patients were divided into groups by age at the time of death
(over or under 65 years). In each group, men and women were studied separately.
Results. The data concerning males clearly revealed a statistically significant larger percentage of myocardial infarction in the anterior wall than in the results from women. Data concerning patients 65 years old or under revealed
a statistically significant larger percentage of myocardial infarction in the anterior wall compared with the results
from patients over 65 years.
Conclusions. Autopsy examination revealed differences in the location of myocardial infarction depending on the
age and sex of patients (Adv Clin Exp Med 2011, 20, 4, 441–445).
Key words: myocardial infarction, autopsy examination, location of myocardial infarction.
Streszczenie
Wprowadzenie. Zawał mięśnia sercowego może wystąpić w każdym wieku, ale prawdopodobieństwo jego
wystąpienia zwiększa się wraz z upływem lat, co jest przede wszystkim związane ze stopniowym rozwojem
miażdżycy. Dodatkowo mężczyźni są w znacznym stopniu bardziej predysponowani niż kobiety, które w wieku
rozrodczym są pod ochronnym działaniem estrogenów. W wielu badaniach diagnostycznych wykazano istotne
zwężenia w naczyniach wieńcowych oraz przedstawiono umiejscowienie zawałów serca. W aspekcie patomorfologicznym istnieje możliwość dokładnego potwierdzenia oraz oceny umiejscowienia śmiertelnego zawału serca na
podstawie badania autopsyjnego.
Cel pracy. Ocena umiejscowienia zawału mięśnia sercowego w aspekcie patomorfologicznym oraz jego korelacja
z wiekiem i płcią pacjenta.
Materiał i metody. Jako główne kryterium kwalifikujące przypadki do badań przyjęto rozpoznanie makroskopowe
oraz mikroskopowe zawału serca w badaniu autopsyjnym. W analizowanej grupie na podstawie protokołów sekcyjnych uzyskano szczegółowe dane o liczbie zawałów, które dotyczyły poszczególnych ścian mięśnia sercowego.
Opierając się na uzyskanych informacjach, pacjentów podzielono na grupy ze względu na wiek w chwili śmierci, tj.
przed i po 65. r.ż. W każdej z grup osobno rozpatrywano kobiety i mężczyzn.
442
Ł. Szylberg, A. Marszałek
Wyniki. Uzyskane wyniki dotyczące mężczyzn jednoznacznie wykazały istotny statystycznie większy udział procentowy zawału ściany przedniej serca w porównaniu z wynikami uzyskanymi u kobiet. Dane dotyczące osób poniżej
lub w wieku 65 lat wykazały istotny statystycznie większy udział procentowy zawału ściany przedniej mięśnia sercowego w porównaniu z wynikami uzyskanymi w grupie osób powyżej 65 lat.
Wnioski. Badanie autopsyjne wykazało różnicę w umiejscowieniu zawałów mięśnia sercowego serca zarówno
w zależności od wieku, jak i płci pacjentów (Adv Clin Exp Med 2011, 20, 4, 441–445).
Słowa kluczowe: zawał mięśnia sercowego, badanie autopsyjne, umiejscowienie zawału mięśnia sercowego.
Myocardial infarction is focal necrosis of the
heart muscle caused by hypoxia. In Poland, coronary heart disease is believed to be responsible
for about 40% of the deaths among middle-aged
males, and (after malignant tumors) is the second
most frequent cause of premature death among
women [1, 2]. Infarction can occur practically at
any age, but the risk increases significantly with
age; this is mainly associated with the progressive
development of atherosclerosis Only about 10%
of all heart attacks occur in people under 40 years
old, and up to 45% of them are in people under 65.
Males are significantly more predisposed to infarction than pre-menopausal women are, due to the
protective effects of estrogen in the reproductive
age period.
Myocardial infarction (MI) most often occurs in
connection with coronary atherosclerosis. Changes
in atherosclerotic plaque are the most common
starting point for thrombus formation and occlusion of the artery. This process leads to myocardial
infarction of the area supplied by the occluded vessel. It is known that so-called right coronary dominance of blood flow is more frequent. Howeve in
40–50% of MI patients narrowing is found in the left
anterior descending coronary artery (LAD), which
supplies the anterior wall of the left ventricule, the
apex of the heart and the front two thirds of the interventricular septum. The circumflex branch of the
left coronary artery (LCX), which has been reported
to be narrowed in 15–20% of MI cases, covers the
lateral wall of the left ventricle, except for the apex
of the heart. The right coronary artery (RCA), in
which narrowing occurs in 30–40% of heart attacks,
covers the posteroinferior wall of the left ventricle,
the posterior part of the interventricular septum
and part of the posterior wall of the right ventricle
in 20% of MI cases
Myocyte necrosis begins after 20–30 minutes
of artery occlusion, and myocardial infarction takes
place within 3 to 6 hours. Macroscopic changes
may be difficult to recognize in an autopsy examination if the patient died less than 8 to 12 hours
after the MI. In the first 4 to 12 hours after a heart
attack it is only possible to identify a small zone
of myocardial whitening (hypoxia). In the next
period, from 12 to 24 hours, the muscle exhibits a distinct pallor with a yellowish center. After
24 hours, the changes take the form of a tan lesion
with a peripheral zone of congestion. However,
in a microscopic examination, the first changes
can already be seen in the first two hours following a heart attack. The evolution of the changes
includes the presence of wavy muscle fibers and
early necrotic lesions, appearing after 6–8 hours.
After this period, fully developed coagulative necrosis is clearly visible. Next there is a process of
clearance of the dead muscle fibers, which reaches
maximum activity within the following 4–7 days.
Within 3 to 6 weeks after this a scar forms. At the
site of a healed myocardial infarction, a thickened
ventricular wall, with hard and gray tissue, is usually found. This corresponds to the presence of
a scar.
The aim of this study was to define the location of myocardial infarction in pathomorphological terms, and to investigate the correlation with
age and gender.
Material and Methods
At the Department of Pathology of the 10th
Military Hospital in Bydgoszcz, Poland, 214 autopsy examinations were performed between January 2006 and February 2010. The main inclusion
criterion used in this study was a macroscopic and
microscopic diagnosis of myocardial infarction
in the autopsy material. The authors analyzed
the post-mortem records of 72 cases from 2006,
44 from 2007, 51 from 2008, 47 from 2009 and
11 from 2010. All cases in which the autopsy took
place over 72 hours after death were rejected.
The resulting study group included 31 men
and 24 women. In 19 cases myocardial infarction
was diagnosed clinically; in 36 the cause of death
was unclear. In the analyzed group, based on postmortem records, the number of myocardial infarctions and data on the specific localization of
myocardial infarction were noted. Infarcts were
detected macroscopically during autopsy examination and were also confirmed by microscopic
examination based on routine hematoxylin and
eosin (H+E) staining. Taking into consideration
only pathomorphological data, there were patients
with infarction of the interventricular septum, the
443
Myocardial Infaction – Age and Gender
anterior wall of the left ventricle, the posterior wall
of the left ventricle, the inferior wall of the left ventricle, the apex of the heart and the right ventricle.
Based on the available clinical data, the patients were divided into groups by age at the time
of death, i.e. above or below 65. In each group,
men and women were studied separately. SPSS
14.0 software was used. For the statistical analysis of the test results, including the nonparametric
Mann-Whitney test at a fixed level of significance
of 0.05.
Results
In the analyzed group of deceased patients
(n = 55) there were 24 women (average age
73 years). Among the female patients myocardial
infarction was found in the interventricular septum in 14 cases, in the anterior wall in 4 cases, in
the posterior wall in 12 cases, in the inferior wall in
one case and in the apex of the heart in 2 cases.
The mean age of the 31 men in the study group
was 65 years, which was significantly lower than
the average age of the women. Among the males
myocardial infarction was found in the interventricular septum in 19 cases, in the anterior wall in
14 cases, in the posterior wall in 12 cases and in
the apex of the heart in 2 cases (Figures 1 and 2).
The data obtained for the males clearly revealed
a statistically significant larger percentage of myocardial infarction in the anterior wall compared
with the women (Table 1). Other data regarding
the location of myocardial infarction did not differ
significantly between women and men.
The analyzed group was then divided according
to age, forming two subgroups. The first consisted
of 19 patients aged 65 years or less, and the second
consisted of 36 patients over 65. In the younger
group, infarction was found in the interventricular septum in 12 cases, in the anterior wall in 10
cases, in the posterior wall in 8 cases and in the
cardiac apex in 2 cases. The older group included
21 cases of infarction in the interventricular sep-
interventricular septum
przegroda międzykomorowa
43% (14)
3%
anterior wall
ściana przednia
12% (4)
posterior wall
ściana tylna
36% (12)
6%
43%
36%
inferior wall
ściana dolna
3% (1)
12%
apex
koniuszek
6% (2)
Fig. 1. Distribution of locations of acute myocardial
infarction in various walls of the heart in women. Data
expressed as percentages; the number of cases given in
brackets
Ryc. 1. Procentowe zajęcie poszczególnych ścian serca
u kobiet z zawałem serca. W nawiasie podano liczbę
przypadków
0%
interventricular septum
przegroda międzykomorowa
40% (19)
4%
anterior wall
ściana przednia
30% (14)
26%
posterior wall
ściana tylna
26% (12)
40%
30%
inferior wall
ściana dolna
0% (0)
apex
koniuszek
4% (2)
Fig. 2. Distribution of locations of acute myocardial
infarction in various walls of the heart in men. Data
expressed as percentages; the number of cases given in
brackets
Ryc. 2. Procentowe zajęcie poszczególnych ścian serca
u mężczyzn z zawałem serca. W nawiasie podano liczbę
przypadków
tum, 8 in the anterior wall, 16 in the posterior wall,
1 in the inferior wall and 2 in the apex of the heart
(Fis 3 and 4). The obtained data for patients aged
65 or less revealed a statistically significant larger
percentage of myocardial infarction in the anterior
wall compared with the results for patients over
65 years (Table 2).
Table 1. Evaluation of the statistical significance of the location of myocardial infarction in men and women.
Tabela 1. Ocena istotności statystycznej umiejscowienia zawału serca u kobiet i mężczyzn
Significance
(Istotność)
NS – not significant.
Myocardial infarction of the interventricular septum
(Zawał przegrody
międzykomorowej)
Myocardial
infarction of the
anterior wall
(Zawał ściany
przedniej)
Myocardial
infarction of the
posterior wall
(Zawał ściany
tylnej)
Myocardial infarction of the inferior
wall
(Zawał ściany
dolnej)
Myocardial
infarction of the
apex
(Zawał
koniuszka)
NS
0.019
NS
NS
NS
444
Ł. Szylberg, A. Marszałek
interventricular septum
przegroda międzykomorowa
38% (12)
anterior wall
ściana przednia
31% (10)
posterior wall
ściana tylna
25% (8)
inferior wall
ściana dolna
0% (0)
apex
koniuszek
6% (2)
0%
6%
25%
38%
31%
interventricular septum
przegroda międzykomorowa
44% (21)
anterior wall
ściana przednia
17% (8)
posterior wall
ściana tylna
33% (16)
inferior wall
ściana dolna
2% (1)
apex
koniuszek
4% (2)
2%
4%
33%
17%
Fig. 3. Distribution of locations of acute myocardial
infarction in various walls of the heart in patients aged
65 or less. Data expressed as percentages; the number
of cases given in brackets
Fig. 4. Distribution of locations of acute myocardial
infarction in various walls of the heart in patients over
age 65. Data expressed as percentages; the number of
cases given in brackets
Ryc. 3. Procentowe zajęcie poszczególnych ścian serca
u osób z zawałem serca w wieku < 65 lat. W nawiasie
podano liczbę przypadków
Ryc. 4. Procentowe zajęcie poszczególnych ścian serca
u osób z zawałem serca w wieku > 65 lat. W nawiasie
podano liczbę przypadków
Table 2. Evaluation of the statistical significance of the location of myocardial infarction in patients aged 65 or less and in
patients over 65
Tabela 2. Ocena istotności statystycznej umiejscowienia zawału serca u osób < 65 lat oraz > 65 lat
Significance
(Istotność)
Myocardial infarction of the interventricular septum
(Zawał przegrody
międzykomorowej)
Myocardial
infarction of the
anterior wall
(Zawał ściany
przedniej)
Myocardial
infarction of the
posterior wall
(Zawał ściany
tylnej)
Myocardial infarction of the inferior
wall
(Zawał ściany
dolnej)
Myocardial
infarction of the
apex
(Zawał
koniuszka)
NS
0.05
NS
NS
NS
NS – not significant.
Discussion
Progress in diagnostics and treatments in developed countries has resulted in increased life expectancy for men and women and an increase in the
number of elderly people. One consequence of this
epidemiological data is an increase in the number
of cases of diseases typical of elderly people, including heart disease. Increasing age is also associated
with the severity of systemic atherosclerosis and
narrowing of the coronary arteries, which leads to
flow limitation and myocardial infarction. In this
study on a group of 55 cases, a significantly higher
proportion of heart attacks occurred in patients
over 65 years old. A correlation was also found between age and the topographic characteristics of
heart disease. A higher percentage of the anterior
wall infarcts (31%) was noted in the patients under
65 years old, which may correlate with more frequent changes in the anterior descending branch
of the left coronary artery. Patients over 65 showed
a greater percentage of myocardial infarction in
the posterior wall (33%), which may indicate more
frequent participation of the right coronary artery
[4, 5]. These results do not confirm the findings
reported by Dąbek et al [3]. Those authors stud-
ied acute coronary syndromes in patients over 80
years old who underwent coronary angiography
to detect critical stenosis of the coronary arteries;
and the most widened vessels found were branches
of the anterior descending coronary artery (38.8%
of the dilated blood vessels), followed by the right
coronary artery (36.1%) and the circumflex branch
(16.6%). The other vessels are the trunk of the left
coronary artery – 8.3% of the dilated blood vessels – and the marginal and posterior branch of the
descending artery – 2.1%. Comparing the results
of clinical results of the present study and those
published by Dąbek et al, it can be suggested that
at older ages, fatal myocardial infarction is more
common in the right coronary artery.
When the study group was divided into subgroups according to gender, a difference of 8 years
in the average age of a heart attack was apparent.
Cardiovascular disease among women develops 10
to 15 years later than in men due to the protective effects of estrogen. The Framingham Study
showed that women under 50 years old suffer
from and/or die of cardiovascular diseases 6 times
less frequently than men [6]. In postmenopausal
women, the risk of developing coronary heart disease increases significantly. It is believed that this
Myocardial Infaction – Age and Gender
is due to the inhibition of the synthesis and secretion of estrogen, which has a protective effect on
the cardiovascular system, primarily on lipid metabolism [7, 8]. Estrogen also affects coagulation
and fibrinolysis, has beneficial antioxidant effects
and regulates the tension of vascular walls [8, 9].
Processes that are known to occur in the post-
445
menopausal period, in combination with research
results showing a lower percentage of anterior wall
involvement in women than in men (12% and 30%
respectively), may suggest more intensive development of atherosclerotic plaque in women’s right
coronary artery. The characteristics of this process
may be related to estrogen imbalances.
References
[1] Kośmicki MA: Choroba niedokrwienna serca w Polsce i na świecie – nierozwiązany w pełni problem. Kardiologia
Oparta na Faktach 2010, 1, 35–48.
[2] www.mz.gov.pl Narodowy Program Zdrowia 2007–2015. Ministerstwo Zdrowia i Opieki Społecznej, Warszawa
2007, 12–13.
[3] Dąbek J, Jakubowski D, Gąsiorz et al.: Acute coronary syndromes in patients over 80 years old. Pol Merk Lek
2007, 22, 514–518.
[4] Abid AR, Rafique S, Tarin SM et al.: Age-related in-hospital mortality among patients with acute myocardial
infarction. J Coll Physicians Surg Pak 2004, 14, 262–266.
[5] Barakat K., Wilkinson P, Deaner A et al.: How should age affect management of acute myocardial infarction?
A prospective cohort study. Lancet 1999, 20, 353, 955–959.
[6] Murabito JM: Women and cardiovascular disease: contributions from the Framingham Heart Study. J Am Med
Womens Assoc 1995, 50, 35–39.
[7] Hu FB, Grodstein F, Hennekens CH et al.: Age at natural menopause and risk of cardiovascular disease. Arch
Intern Med 1999, 159, 1061–1066.
[8] Kozakiewicz K, Wycisk A et al.: Hormonal replacement therapy and selective estrogen receptor modulators in
prevention of cardiovascular disease. Wiad Lek 2006, 59, 377–382.
[9] Mendelsohn ME, Karas RH et al.: The protective effects of estrogen on the cardiovascular system. N Engl J Med
1999, 340, 1801–1811.
Address for correspondence
Andrzej Marszałek
Department of Clinical Pathomorphology CM UMK
Skłodowskiej-Curie 9
85-094 Bydgoszcz
Poland
Tel.: +48 52 58 54 200
E-mail: [email protected]
Conflict of interest: None declared
Received: 7.03.2011
Revised: 5.04.2011
Accepted: 1.08.2011